Cannabis “shows promise” as fibromyalgia treatment, study finds

A literature review of fibromyalgia and cannabis research indicates that CBD and THC could be effective in managing the hard-to-treat condition, but more research is needed.

Fibromyalgia affects millions of people worldwide and increasing numbers of patients are turning to cannabis to manage the condition. People suffering from the condition usually experience a range of symptoms including widespread chronic pain, fatigue, stiffness, poor sleep and cognitive dysfunction, referred to as ‘fibro fog’.

Despite its prevalence, the condition is difficult to treat and often goes misdiagnosed or undiagnosed completely. For the average fibromyalgia patient, diagnosis takes around 2.3 years.

A review of preclinical and clinical research on the effect of cannabinoids on fibromyalgia has found that cannabis and cannabis-based medicines “show promise” therapeutically. This supports a growing amount of anecdotal evidence from fibromyalgia patients who have found respite from their condition thanks to cannabis-based medicines.

Gaps in the literature, however, remain a barrier to cannabis being used as a formal treatment, the study concluded. There is a particular need for further animal models, balanced studies to eliminate sex bias in preclinical research and “better translation” between preclinical and clinical studies.

“Limitations in methodology and lack of longitudinal studies to assess efficacy and tolerability preclude the current recommendation for their use in patients with FM.” the authors wrote in the paper, published in the journal Pharmacology & Therapeutics.

The study indicated that synthetic THC and CBD may have therapeutic benefits, but the authors stressed that oral administration of cannabinoids has its limitations, notably the low bioavailability of CBD and THC oils when ingested.

Based on the reviewed literature, the authors said inhaled cannabis is shown to be the most beneficial for pain, sleep and overall quality of life but a lack of scientific understanding of the long-term effects remains a limitation.

Other factors that prevent the recommendation of cannabis as a treatment include “significant variations in methodological approach, herbal cannabis preparations, treatment duration, small sample sizes and a narrow demographic of patients”.

The paper noted that synthetic cannabinoids may also lack the entourage effect, which suggests that the array of phytocannabinoids and terpenes in the cannabis plant work in conjunction to enhance the therapeutic benefits of CBD and THC.

Another route of administration that could be of benefit to fibromyalgia patients is transdermal skin patches for localised musculoskeletal pain, the authors said.

“This method could avoid first-pass metabolism and offer additional benefits such as reduced frequency of dosing, slow release over a prolonged period to minimise adverse effects, and less abuse potential,” the researchers wrote in the paper’s conclusion.

Based on the available research, the authors of the study stated that it is difficult to draw any “robust conclusions” regarding the use of cannabis in treating fibromyalgia, however promising patient outcomes suggest the potential is there.

“There is an overarching need to conduct more [randomised controlled trials] with increased sample sizes, rigorous dosing regimens and consistency with the inclusion/exclusion criteria, more extensive outcome measures and inclusion of longitudinal studies to assess efficacy and tolerability,” the authors concluded.